A State Rarity Rank of S2 means: Typically 6 to 20 occurrences, few remaining individuals, acres, or miles of stream, or factors demonstrably make it very vulnerable in New York State.

Global Rarity Rank:G4

A Global Rarity Rank of G4 means: Apparently secure globally, though it may be quite rare in parts of its range, especially at the periphery.

Did you know?
Lampreys are ancient fish, which have persisted almost unchanged for about 250 million years. Interestingly, they were the first vertebrates. Ichthyomyzon may be the most primitive genus of lampreys (Moen 2002; Smith 1985).

The northern brook lamprey is rare in New York because of its limited distribution in the state. When the state rarity rank of S1 was assigned in 1983, the fish was confirmed in only one creek in western New York. Now it is confirmed in 10 brooks, creeks, and small rivers in New York, but it is limited to two areas of the state, the Lake Erie watershed in western New York, and the Lake Champlain and St. Lawrence River watersheds in northern New York (New York Natural Heritage Program 2008). Specimens that have been caught from a few other creeks and rivers in the state have been thought to be this species, but they were difficult to identify and could not be confirmed. Although additional information on the status of the northern brook lamprey in New York State is needed, and although the fish may be discovered in additional creeks and small rivers with additional survey effort, it is likely that it is indeed rare and that its distribution in the state is limited (Doug Carlson, pers. comm. 2009; Carlson 2001).